Within the past decade, the surgical use of lasers to cut, cauterize and ablate tissue has been developing rapidly. Advantages to the surgical use of laser energy lie in increased precision and maneuverability over conventional techniques. Additional benefits include prompt healing with less post-operative pain, bruising, and swelling. Lasers have become increasingly important, especially in the fields of Ophthalmology, Gynecology and Dermatology, as a less invasive, more effective surgical therapeutic modality which allows the reduction of the cost of procedures and patient recovery times due to diminished tissue trauma, bleeding, swelling and pain. The CO.sub.2 laser has achieved wide spread use in surgery for cutting and vaporizing soft tissue. The CO.sub.2 laser energy has a very short depth of penetration, however, and does not effectively cauterize small blood vessels. Other means such as electrocautery must be used to control and minimize blood loss. The Neodynium-YAG laser, on the other hand, because of its greater depth of tissue penetration, is very effective in vaporizing soft tissue and cauterizing small blood vessels. But as a result of this great depth of tissue penetration, the Neodynium-YAG laser has achieved limited use in the field of soft tissue surgery because of the possibility of unwanted damage to deeper tissues in the path of the laser energy beam.
Liposuction, a surgical technique of removing unwanted fat deposits for the purpose of body contouring, has achieved widespread use. In the United States, over 100,000 liposuction procedures were performed in 1989 alone. This technique utilizes a hollow tube or cannula with a blunt tip and a side hole or tissue aspiration inlet port near its distal end. The proximal end of the cannula has a handle and a tissue outlet port connected to a vacuum aspiration pump. In use, a small incision is made, the cannula tip and adjacent tissue inlet port is passed beneath the surface of the skin into the unwanted fat deposit. The vacuum pump is then activated drawing a small amount of tissue into the lumen of the cannula via the inlet port. Longitudinal motion of the cannula then removes the unwanted fat by a combination of sucking and ripping actions. This ripping action causes excessive trauma to the fatty tissues resulting in considerable blood loss and post-operative bruising, swelling and pain. Proposed advances in the techniques and apparatus in this field have been primarily directed to the design of the aspiration cannula, and more recently have involved the application of ultrasound and irrigation to melt and solubilize fatty tissue or the use of an auger, within the lumen of the cannula, to facilitate soft tissue removal. These proposed advances do not adequately address the goals of the surgical procedure: the efficient and precise removal of soft tissue with minimal tissue trauma and blood loss.
This invention utilizes a modification of a suction lipectomy cannula, already in clinical use, to position soft tissue within a protective chamber, allowing a Neodynium-YAG laser energy beam to cut and cauterize the soft tissue without fear of unwanted damage to surrounding or deeper tissues. This invention renders the removal of soft tissue safer, more precise, faster (and thus more efficient) and minimizes tissue trauma by eliminating the ripping action inherent in the conventional liposuction method.
This invention, by eliminating the ripping action of the conventional liposuction method, expands the scope of soft tissue removal. Currently, the liposuction method is limited to the aspiration of fat. Other soft tissues, such as breast tissue, lymphangiomas, and hemangiomas are too dense or too vascular to allow efficient and safe removal utilizing the liposuction method. This invention with the precise cutting and coagulating action of the Neodynium-YAG laser, within the cannula, permits the removal of these dense or vascular soft tissues.
This invention, by controlling the depth of penetration of the Neodynium-YAG laser within the protective aspiration cannula, expands the surgical applicability of the Neodynium-YAG laser. This laser can now be used, for example, in the precise removal of brain tissue without fear of unwanted damage to surrounding or deeper tissues. At this time, the CO.sub.2 laser is extensively used for the vaporization of brain tumors, but because of its inability to effectively coagulate blood vessels, other methods such as electrocautery must be used to control blood loss during the procedure. In addition, because the vaporization of tissue generates large volumes of noxious and potentially toxic smoke, expensive, noisy and cumbersome suction devices must be used to eliminate the smoke from the surgical field. This invention, by utilizing the more effective coagulating power of the Neodynium-YAG laser, within the aspiration cannula, permits the combined action of tissue vaporization, control of blood loss, and elimination of smoke from the surgical field.
The basic design of the present Laser Soft Tissue Aspiration Device of this invention can be scaled down to permit soft tissue aspiration in other parts of the body. For example, an appropriately sized version of the present device can be used for safe removal of scar tissue from within the eye or adjacent to the retina and lens tissue from within the eye. Other appropriately sized and scaled versions of the present device may also be used for the removal of other unwanted soft tissues within the body. For example: removal of unwanted tracheal tissue, such as bronchial adenomas; removal of polyps and other soft tissue from within the lumen of the gastrointestinal tract; for endometrial ablations within the uterus; in conjunction with laparoscopic techniques to remove endometrial tissue with the abdomen.